1957-2024 Kenai Swan Exploratory Data Summaries

Data Files

all_raw.csv = compiled, raw data (maintains all fields from historic database, plus one added field “gps_ident” for waypoint values) (see Compilation below)

derived.csv = compiled data, condensed to fewer fields, with some modifications for data clean-up and some added, derived fields (see Cleaning and Deriving below)

Record of Data Manipulation

Compilation

  • Compiled/standardized 10 data tables: 1957-2015 database file, 2017 nesting, 2018 productivity, 2019 productivity, 2022 nesting, 2022 productivity, 2023 nesting, 2023 productivity, 2024 nesting, and 2024 productivity
  • Entered 2017 nesting and 2022 nesting data from raw
  • Corrected survey dates for 2022 productivity and 2024 productivity data
  • Added pilot, observer, aircraft, start time, and end time to post-2015 data, if missing

Cleaning

  • Reordered columns for clarity
  • Concatenated two comments fields into one
  • Corrected adults values of 0 that should not have been 0 (comment: “Swans on nest.”, incubating: 1) -> converted to count of 1
  • Removed values from pilot column that were start times rather than names
  • Converted some NA (blank) values to 0 values
    • For spring survey, if adults were counted but nests were NA, made nests a 0 observation, or if nests were counted but adults were NA, made adults 0.
    • For fall survey, if adults were counted but cygnets were NA, made cygnets 0, or if cygnets were counted but adults were NA, made adults 0.
  • Removed duplicate observations (rows) from 2013 fall productivity (08/29/2013) survey data (same data x 2)
    • Note: It appears that the spring survey for 2013 has most - but not all - duplicates as well, if you truncate all lat-lons to the same number of decimal places before matching up. The June duplicates have not yet been filtered out.

Deriving

  • Column for survey type: spring nesting (May/June), early brood (July), late brood (August/September), out of bounds (any other month)
  • Column to identify duplicates (repeats = the number of times an exact coordinate pair shows up in a single survey period in a single year)
  • Several columns of spatially joined (via intersect) landable lake data

Exploratory Summaries

Method Consistency

Number of days spent surveying per survey period:

years nesting early_brood late_brood out_of_bounds
1957 17 3 2 2
1958 12 2 3 0
1959 8 6 8 10
1960 11 5 2 3
1961 12 3 4 9
1962 9 2 7 9
1963 21 2 2 2
1964 9 3 4 0
1965 31 15 13 2
1966 22 8 14 0
1967 26 8 12 3
1968 24 5 5 2
1969 22 7 12 8
1970 19 0 6 15
1971 30 3 10 14
1972 22 4 11 3
1973 11 5 16 5
1974 23 8 9 7
1975 16 10 12 5
1976 9 2 4 2
1977 8 4 9 0
1978 11 4 8 2
1979 14 3 4 4
1980 3 3 4 6
1981 3 2 3 0
1982 3 2 2 0
1983 6 3 3 2
1984 5 11 5 0
1985 3 2 3 1
1986 6 1 2 0
1987 3 3 2 0
1988 5 1 2 2
1989 4 1 1 0
1990 1 1 2 0
1991 1 1 1 0
1992 1 2 1 0
1993 1 2 0 0
1994 3 4 4 0
1995 3 2 5 0
1996 5 2 3 0
1997 4 2 2 0
1998 3 4 3 0
1999 3 2 3 0
2000 5 3 3 0
2001 3 2 1 0
2002 2 3 2 0
2003 0 0 1 0
2004 0 0 3 0
2005 3 3 5 0
2006 1 0 2 0
2007 1 0 2 0
2008 0 0 3 0
2009 0 0 2 0
2010 2 2 1 0
2011 0 0 3 0
2013 3 0 1 0
2015 4 0 2 0
2017 3 0 0 0
2018 0 0 1 0
2019 0 0 1 0
2022 3 0 2 0
2023 3 0 1 0
2024 3 0 2 0

Census vs. Nest-Only (Spring Survey Only)

Was the spring survey nest-only or census? One indicator could be whether there are exclusively observations recorded that have nests observed.

Years where all adult counts have a nest observation: 2010

Census vs. Return to a Set Location (nest or lake)

Were the surveys censuses or revisits to pre-set locations (e.g. lakes, nests)? One indicator could be whether locations/observations were recorded with no swans/nests.

Spring survey years with “no swan” observations: 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1971, 1972, 1973, 1974, 1975, 1976, 1978, 1979, 1980, 1981, 1982, 1986, 1993, 1997, 1999, 2010, 2015

Fall survey years with “no swan” observations: 1957, 1958, 1959, 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1973, 1975, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1991, 1992, 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2009, 2010, 2018, 2022, 2023, 2024

Disparities in Counts

Totals/Summaries for Review

Summary productivity info:

years nesting_swans num_nests breeding_swans cygnets avg_brood_size
1957 29 15 19 30 3.000000
1958 66 33 26 48 3.692308
1959 18 10 55 111 3.468750
1960 25 13 2 1 1.000000
1961 69 35 38 65 3.250000
1962 51 28 89 148 3.288889
1963 72 42 36 56 3.111111
1964 59 30 33 55 3.235294
1965 206 110 103 251 4.114754
1966 258 133 113 224 3.733333
1967 190 100 61 101 3.156250
1968 125 65 12 22 3.666667
1969 115 59 72 104 2.888889
1970 44 30 38 67 3.526316
1971 155 89 48 106 4.416667
1972 51 29 50 73 2.807692
1973 65 36 77 136 3.487179
1974 79 41 28 58 3.866667
1975 98 55 54 70 2.592593
1976 21 12 6 22 4.400000
1977 16 9 50 87 3.480000
1978 58 29 46 91 3.956522
1979 87 45 32 46 2.875000
1980 46 25 42 74 3.523810
1981 41 30 26 45 3.461539
1982 43 23 40 65 3.250000
1983 66 33 42 75 3.571429
1984 75 38 79 129 3.225000
1985 55 29 22 40 3.636364
1986 70 36 32 62 3.444444
1987 75 38 32 66 4.125000
1988 85 43 46 75 3.260870
1989 74 40 41 57 2.714286
1990 4 2 50 87 3.480000
1991 8 4 52 86 3.185185
1992 2 1 60 97 3.233333
1993 26 14 NA NA NA
1994 51 27 58 96 3.310345
1995 72 36 55 81 2.892857
1996 80 40 53 92 3.407407
1997 78 39 64 102 3.187500
1998 106 53 72 143 3.972222
1999 103 52 64 102 3.090909
2000 68 34 72 112 3.111111
2001 106 53 51 87 3.346154
2002 77 40 36 41 2.277778
2003 NA NA 32 49 3.062500
2004 NA NA 60 96 3.096774
2005 111 60 103 172 3.307692
2006 2 1 8 18 3.600000
2007 2 1 23 35 2.916667
2008 NA NA 102 152 2.980392
2009 NA NA 10 19 3.800000
2010 0 0 44 61 2.772727
2011 NA NA 106 174 3.222222
2013 174 96 43 55 2.500000
2015 99 60 60 106 3.533333
2017 82 41 NA NA NA
2018 NA NA 40 57 2.850000
2019 NA NA 47 68 2.833333
2022 87 45 45 74 3.217391
2023 93 46 39 48 2.400000
2024 89 45 53 72 2.666667

Note that some observations may have >1 cygnet and >2 adults. For these observations, you would only want to count 2 of the adults as breeding adults.

Summary adult swan totals by survey type:

years spring summer fall
1957 100 22 19
1958 205 72 31
1959 138 68 92
1960 156 104 4
1961 441 42 61
1962 1288 43 143
1963 607 50 40
1964 119 38 39
1965 426 102 111
1966 382 76 115
1967 228 72 67
1968 173 22 16
1969 178 52 91
1970 233 NA 78
1971 805 26 112
1972 179 53 102
1973 136 42 116
1974 243 57 35
1975 234 75 150
1976 138 8 6
1977 28 16 88
1978 102 45 46
1979 145 63 72
1980 60 57 49
1981 51 76 47
1982 126 55 81
1983 121 69 77
1984 126 59 118
1985 162 74 116
1986 122 74 54
1987 112 96 40
1988 116 16 69
1989 170 58 116
1990 116 67 107
1991 125 70 97
1992 150 93 135
1993 132 60 NA
1994 160 138 154
1995 181 102 189
1996 158 128 135
1997 162 129 116
1998 144 124 96
1999 205 137 74
2000 225 84 244
2001 187 99 57
2002 142 124 52
2003 NA NA 82
2004 NA NA 272
2005 227 147 389
2006 2 NA 20
2007 2 NA 49
2008 NA NA 250
2009 NA NA 18
2010 189 216 54
2011 NA NA 250
2013 456 NA 192
2015 196 NA 187
2017 209 NA NA
2018 NA NA 114
2019 NA NA 142
2022 170 NA 69
2023 171 NA 64
2024 173 NA 63

Plot spring adults over time:

Plot spring nests over time:

Plot fall adults over time:

Outlier observations

Subset of data with adult counts > 10 in a single observation:

sample_date latitude longitude adults juveniles cygnets nest_observed eggs comments aircraft pilot observer start_time stop_time survey_type repeats lake_name lake_landable lake_meters lake_rule
59 1961-10-17 60.46750 -150.5108 11 2 NA NA NA NA NA NA NA 8:55 16:00 out of bounds 9 NA NA NA NA
198 1971-04-30 60.71315 -151.1968 11 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
280 1976-05-05 60.53552 -150.7572 11 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
4555 2004-08-24 60.30633 -150.5261 11 NA 0 NA NA NA NA NA NA 11:45 15:40 late brood 3 Harvey Lake YES 3607.185 Open to Aircraft in Wilderness
5347 1985-09-06 60.75870 -150.3451 11 NA 0 NA NA NA NA NA NA NA NA late brood 1 NA NA NA NA
31 1959-04-17 60.46750 -150.5108 12 4 NA NA NA Mouth of Skilak Lk NA NA NA NA NA out of bounds 6 NA NA NA NA
33 1975-04-18 60.46750 -150.5108 12 NA NA NA NA NA NA NA NA NA NA out of bounds 4 NA NA NA NA
143 1971-04-26 60.68650 -150.9923 12 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
213 1962-05-02 60.38287 -151.2885 12 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
260 1971-04-23 60.53552 -150.7572 12 NA NA NA NA NA NA NA NA NA NA out of bounds 4 NA NA NA NA
267 1962-05-02 60.52331 -151.2270 12 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
9234 1960-10-07 60.89929 -150.1204 12 3 NA NA NA May be tundra swans NA NA NA NA NA out of bounds 1 NA NA NA NA
9241 1963-10-11 60.40458 -150.4450 12 NA NA NA NA NA NA NA NA NA NA out of bounds 1 Skilak Lake YES 86844.942 Open to Aircraft in Non-Wilderness
54 1963-10-11 60.46750 -150.5108 13 NA NA NA NA Trumpeter and tundra swans NA NA NA NA NA out of bounds 2 NA NA NA NA
2960 1961-05-01 60.54134 -150.7497 13 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
40 1975-04-22 60.46750 -150.5108 14 NA NA NA NA NA NA NA NA NA NA out of bounds 4 NA NA NA NA
53 1995-05-30 60.46750 -150.5108 14 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
6054 1992-05-29 60.76881 -150.7111 14 NA NA 0 NA NA Cessna 206 NA NA NA NA spring nesting 1 NA NA NA NA
7597 1985-09-06 60.64335 -150.6745 14 NA 0 NA NA NA NA NA NA NA NA late brood 1 Meadow Lake YES 2757.558 Closed to Aircraft in Wilderness
2964 1963-05-02 60.46580 -150.5229 15 NA NA 0 NA NA NA NA NA 9:45 14:40 spring nesting 1 NA NA NA NA
2959 1974-04-28 60.54134 -150.7497 16 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
190 1971-05-11 60.59756 -150.8347 17 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
3137 2005-08-17 60.76854 -150.1334 17 NA 0 NA NA NA NA NA NA 10:00 15:20 late brood 1 NA NA NA NA
110 1971-04-19 60.45937 -150.5437 18 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
1000 1988-10-07 60.76444 -150.7258 18 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
924 1960-05-13 60.95315 -150.2713 19 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
43 1974-04-26 60.46750 -150.5108 20 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
55 1963-10-11 60.46750 -150.5108 20 NA 31 NA NA At least 10 family groups, trumpeter and tundra swans NA NA NA NA NA out of bounds 2 NA NA NA NA
2951 1979-04-18 60.46580 -150.5229 20 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
2961 1974-05-01 60.54134 -150.7497 20 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
172 1974-04-26 60.41589 -150.4837 21 NA NA NA NA NA NA NA NA NA NA out of bounds 1 Skilak Lake YES 86844.942 Open to Aircraft in Non-Wilderness
178 1970-04-27 60.55239 -150.4947 22 NA NA NA NA NA NA NA NA NA NA out of bounds 1 Afonasi Lake YES 4092.100 Closed to Aircraft in Non-Wilderness
188 1970-04-30 60.59756 -150.8347 22 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
219 1971-04-26 60.92387 -150.1895 22 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
36 1971-04-21 60.46750 -150.5108 23 NA NA NA NA NA NA NA NA NA NA out of bounds 6 NA NA NA NA
208 1971-04-26 60.38287 -151.2885 23 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
264 1971-04-30 60.53876 -151.2291 23 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
3199 1988-10-07 60.54134 -150.7497 23 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
27 1959-04-13 60.46750 -150.5108 24 NA NA NA NA NA NA NA NA NA NA out of bounds 6 NA NA NA NA
189 1970-04-30 60.74503 -150.8020 24 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
34 1961-04-20 60.46750 -150.5108 27 1 NA NA NA NA NA NA NA NA NA out of bounds 9 NA NA NA NA
28 1961-04-13 60.46750 -150.5108 28 3 NA NA NA NA NA NA NA NA NA out of bounds 9 NA NA NA NA
212 1959-05-01 60.44703 -151.2338 28 NA NA 0 NA Marsh south of Kenai NA NA NA NA NA spring nesting 1 NA NA NA NA
35 1967-04-21 60.46750 -150.5108 31 NA NA NA NA NA NA NA NA NA NA out of bounds 3 NA NA NA NA
41 1962-04-23 60.46750 -150.5108 32 NA NA NA NA NA NA NA NA NA NA out of bounds 5 NA NA NA NA
230 1961-05-01 60.92387 -150.1895 32 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
215 1969-04-22 60.38474 -151.3027 33 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
217 1976-04-24 60.38474 -151.3027 33 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
236 1963-05-02 60.38474 -151.3027 33 NA NA 0 NA NA NA NA NA 9:45 14:40 spring nesting 1 NA NA NA NA
7994 1995-08-11 60.65252 -150.7219 33 NA 0 NA NA NA NA NA NA NA NA late brood 1 Big Mink Lake YES 3850.972 Closed to Aircraft in Wilderness
220 1971-04-30 60.92387 -150.1895 34 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
222 1961-05-01 60.38474 -151.3027 35 NA NA 0 NA Of 35 swans potentially 30 were tundra swans NA NA NA NA NA spring nesting 1 NA NA NA NA
4114 1962-05-02 60.58344 -150.5374 35 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
49 1971-05-10 60.46750 -150.5108 38 NA NA 0 NA NA NA NA NA NA NA spring nesting 3 NA NA NA NA
209 1971-04-30 60.38287 -151.2885 38 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
2966 1963-05-06 60.54134 -150.7497 38 NA NA 0 NA NA NA NA NA 10:46 14:30 spring nesting 1 NA NA NA NA
234 1962-05-02 60.74354 -151.0226 40 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
277 1971-05-03 60.53876 -151.2291 40 NA NA 0 NA NA NA NA NA NA NA spring nesting 2 NA NA NA NA
279 1971-05-05 60.53876 -151.2291 40 NA NA 0 NA NA NA NA NA NA NA spring nesting 2 NA NA NA NA
9211 1962-05-02 60.89929 -150.1204 45 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
176 1970-04-27 60.59578 -150.8110 50 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
302 1982-05-02 60.90292 -150.1797 50 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
263 1971-04-30 60.53552 -150.7572 51 NA NA NA NA NA NA NA NA NA NA out of bounds 4 NA NA NA NA
144 1971-04-26 60.75960 -150.1724 60 NA NA NA NA NA NA NA NA NA NA out of bounds 1 Scenic Lake YES 3001.582 Open to Aircraft in Wilderness
265 1976-05-01 60.53876 -151.2291 60 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
273 1963-05-02 60.53552 -150.7572 67 NA NA 0 NA NA NA NA NA 9:45 14:40 spring nesting 1 NA NA NA NA
2958 1963-04-26 60.46580 -150.5229 72 NA NA NA NA NA NA NA NA 8:45 11:47 out of bounds 1 NA NA NA NA
45 1961-05-01 60.46750 -150.5108 74 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
276 1971-05-03 60.53552 -150.7572 80 NA NA 0 NA NA NA NA NA NA NA spring nesting 2 NA NA NA NA
2955 1983-04-23 60.54134 -150.7497 80 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
2957 1983-04-25 60.54134 -150.7497 80 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
278 1971-05-05 60.53552 -150.7572 84 NA NA 0 NA NA NA NA NA NA NA spring nesting 2 NA NA NA NA
275 1975-05-02 60.53552 -150.7572 90 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
292 1980-10-10 60.53552 -150.7572 100 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
38 1959-04-22 60.46750 -150.5108 109 12 NA NA NA NA NA NA NA NA NA out of bounds 6 NA NA NA NA
281 1970-05-07 60.53552 -150.7572 115 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
706 1962-05-02 60.53558 -150.4635 119 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 Watson Lake YES 2234.058 Closed to Aircraft in Non-Wilderness
9208 1960-10-06 60.90911 -150.1756 120 26 NA NA NA NA NA NA NA 15:00 16:30 out of bounds 1 NA NA NA NA
237 1963-05-02 60.91772 -150.1026 143 NA NA 0 NA NA NA NA NA 9:45 14:40 spring nesting 1 NA NA NA NA
262 1970-04-27 60.53552 -150.7572 150 NA NA NA NA NA NA NA NA NA NA out of bounds 2 NA NA NA NA
46 1971-05-03 60.46750 -150.5108 220 NA NA 0 NA NA NA NA NA NA NA spring nesting 3 NA NA NA NA
2962 1962-05-02 60.46580 -150.5229 222 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
37 1976-04-21 60.46750 -150.5108 250 NA NA NA NA NA NA NA NA NA NA out of bounds 1 NA NA NA NA
235 1962-05-02 60.91772 -150.1026 260 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
44 1971-04-30 60.46750 -150.5108 370 NA NA NA NA NA NA NA NA NA NA out of bounds 6 NA NA NA NA
268 1962-05-02 60.53552 -150.7572 400 NA NA 0 NA NA NA NA NA NA NA spring nesting 1 NA NA NA NA
42 1971-04-26 60.46750 -150.5108 420 NA NA NA NA NA NA NA NA NA NA out of bounds 6 NA NA NA NA

Frequency table for adult counts >10 in a single observation:

Var1 Freq
11 5
12 8
13 2
14 4
15 1
16 1
17 2
18 2
19 1
20 4
21 1
22 3
23 4
24 2
27 1
28 2
31 1
32 2
33 4
34 1
35 2
38 3
40 3
45 1
50 2
51 1
60 2
67 1
72 1
74 1
80 3
84 1
90 1
100 1
109 1
115 1
119 1
120 1
143 1
150 1
220 1
222 1
250 1
260 1
370 1
400 1
420 1

Note: many high counts come from observations in out-of-bounds survey timing

Note: several high counts have comments suggesting the observation includes tundra swans

Note: no obvious cut-off threshold to filter out high counts

Duplicate location observations

Number of duplicate coordinates for each survey period:

Meaning the number of observations where the exact coordinate for the observation shows up multiple times within that survey

years nesting early_brood late_brood out_of_bounds
1957 55 2 2 2
1958 114 36 8 NA
1959 57 27 27 10
1960 30 43 0 0
1961 91 0 4 25
1962 60 4 53 21
1963 109 4 4 2
1964 34 11 18 NA
1965 212 47 43 0
1966 187 36 44 NA
1967 121 37 19 3
1968 88 4 0 0
1969 85 18 26 5
1970 48 NA 11 12
1971 130 2 25 24
1972 67 13 15 2
1973 44 4 31 0
1974 78 19 7 11
1975 65 16 13 4
1976 22 0 2 0
1977 4 0 12 NA
1978 27 0 13 2
1979 40 6 13 2
1980 2 2 2 5
1981 0 0 0 NA
1982 2 0 0 NA
1983 7 6 2 2
1984 0 3 16 NA
1985 26 3 4 0
1986 4 0 4 NA
1987 0 0 0 NA
1988 7 0 0 0
1989 24 0 2 NA
1990 0 0 0 NA
1991 2 0 0 NA
1992 0 2 0 NA
1993 2 0 NA NA
1994 0 0 0 NA
1995 2 0 2 NA
1996 4 6 4 NA
1997 14 4 6 NA
1998 0 0 0 NA
1999 6 2 0 NA
2000 7 0 11 NA
2001 2 0 0 NA
2002 4 6 2 NA
2003 NA NA 4 NA
2004 NA NA 26 NA
2005 10 4 11 NA
2006 0 NA 0 NA
2007 0 NA 2 NA
2008 NA NA 0 NA
2009 NA NA 2 NA
2010 14 136 8 NA
2011 NA NA 118 NA
2013 0 NA 0 NA
2015 0 NA 0 NA
2017 0 NA NA NA
2018 NA NA 0 NA
2019 NA NA 0 NA
2022 0 NA 0 NA
2023 0 NA 0 NA
2024 0 NA 0 NA

Some duplicate coordinates may be due to data being entered twice, such as for 2013. Duplicates in older (esp. pre-GPS) data may be due to assigning lakes or broad areas to a single coordinate. Some of these duplicates may be attributed to multiple observations on a single lake OR to repeat visits to locations during a survey period. If coordinates were recorded with different levels of precision (as in number of decimal places), this can prevent duplicates from being identified. More investigation required.

Spatial Coverage Consistency

Overall, fairly consistent throughout history.

Note that the 2018 productivity survey and a few 2022 nesting survey observations did not have saved coordinates, so they are missing from the maps.

Note: only north appears surveyed in 2015 and 2019

2015

2019

Note: low survey coverage and out-of-bounds Homer observation in 2006

2006

Lake Analysis

Annual Occurrence Tables

Note that the “Unnamed” lake lumps together all lakes where landable is TRUE but lake name is blank.

Open to Aircraft; in Non-Wilderness

lakes adults cygnets nests
Beaver Lake 1960 1962 1969 1970 1971 1972 1973 1974 1975 1979 1980 1982 1983 1984 1987 1989 1990 1991 1992 1993 1994 1995 2002 2004 2005 2006 2007 2008 2010 2011 2013 2015 2019 2024 1970 1973 1974 1975 1979 1984 1989 1990 1991 1992 1993 1994 1995 2002 2006 2007 2008 2010 2011 2024 1969 1970 1973 1974 1975 2002 2024
Ice Lake 1962 1992 1996 2013 2015 2013 2015
Skilak Lake 1963 1974 1975 2010 2024
Snipe Lake 1957 1958 1960 1961 1962 1963 1975 1983 1984 1990 1992 1997 2000 2003 2013 2015 1957 1958 1961 2000 1957 1958 1961 2000 2015
Bear Lake 1961 1970 1982 2000 2001 2008 2009 2013 2015 2022 2000 2008 2009 1982 2001 2015 2022
Shadura Lake 1957 1971 1987 2000 2010 1957
Unnamed 1958 1959 1960 1961 1962 1963 1964 1965 1966 1969 1970 1971 1972 1973 1975 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2004 2005 2008 2010 2011 2013 2015 2022 1958 1961 1962 1963 1964 1965 1966 1970 1973 1977 1978 1980 1981 1984 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2001 2004 2008 2010 2013 2015 1958 1961 1962 1963 1964 1965 1966 1969 1971 1973 1975 1978 1979 1980 1981 1983 1984 1985 1986 1987 1988 1989 1994 1995 1996 1997 1998 1999 2001 2022
Gull Lake 1959 1960 1961 1966 1980 1984 1985 1995 1996 2000 2001 1959 1966 1980 1984 1996 1984
Krein Lake 1965 1966 1967 1969 1970 1973 1988 1990 2011 1965 1966 1967 1969 1970 2011 1965 1966 1967 1969 1970 1988
Quill Lake 1959 1963 1966 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1979 1980 1981 1982 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2003 2004 2005 2007 2010 2015 2022 1959 1963 1966 1968 1969 1970 1971 1976 1977 1980 1981 1982 1987 1988 1989 1991 1993 1998 1999 2000 2001 2003 2005 2007 1968 1969 1970 1971 1973 1974 1975 1976 1977 1979 1980 1981 1982 1984 1985 1988 1989 1994 1995 1996 1998 1999 2001 2015 2022
Crane Lake 1965 1984 1991
Stormy Lake 1960 1961 1962 1964 1966 1967 1971 1973 1988 2013 2015 1960 1961 1962 1964 1966 1973 1960 1961 1964 1966 1967 2015
Lark Lake 1958 1959 1995 2004 2004
Two Island Lake 1983 1985 1987 1994 1995 1996 1998 2003 2010 2017 2022 1995 1996 1998 2006 2010 2022 1985 1987 1996 1998 2017 2022
Flat Lake 1962 1970 1973 1980 1981 1985 1987 1990 1991 2000 2004 1980 1990
Warbler Lake 1960 1961 1972 1974 1990 1999 2000 2005 1972
Barbara Lake 1977 1989 1997 2000 2002 2010 2023 2023 1997 2002 2023
Mink Creek Lake 1957 1958 1959 1962 1965 1966 1967 1969 1970 1974 1975 1978 1979 1981 1984 1986 2013 2019 1957 1959 1965 1966 1967 1969 1970 1974 1978 1979 1981 1984 1986 2019 1957 1958 1965 1969 1974 1978 1979
Doroshin Lake 1958 1965 1984 1986 1987 1988 2015 2017 2022 1965 1984 1984 1986 1987 1988 2017 2022
Cow Lake 1968 1970 1972 1990 2002 2010 2013 2022 1968 1970 1990
West Finger Lake 1985 2010 2022 2023 2023 2023
Goose Lake 1991 2010 2022 2024 1991 2022 2024 2022 2024
Chick Lake 2002 2010 2002
Snag Lake 1979 2010
Trapper Joe Lake 1958 1961 1962 1963 1969 1970 1971 1986 1989 1991 1992 1994 1996 1997 2009 2013 2024 1969 1986 1991 1992 1996 1997 2009 2013
Campfire Lake 1957 1959 1960 1961 1962 1963 1965 1967 1973 1975 1979 1980 1982 1983 1984 1985 1987 1990 1991 1992 1994 1995 1996 1997 1998 1999 2001 2002 2005 2013 2015 2022 2024 1957 1959 1960 1962 1965 1973 1975 1979 1980 1982 1986 1987 1990 1991 1992 1994 1995 1996 1997 1998 1999 2001 2005 2024 1959 1960 1961 1962 1973 1996 1998 1999 2001 2022 2024
Sportfish Lake 1993 1997 2003 2005 2024 2005
Torpedo Lake 1997 2004 2005 2010 2005 2005
Yugok Lake 1993
Gooseneck Lake 1975 1987 1989 1992 1993 1996 2008 2011 1989 1992 2008 2011
Plover Lake 1970 1974 1979 1982 1991
Akula Lake 1971 1991 1994 1996 1998 2005 2013 2013
Middle Finger Lake 1959 1962 1965 1975 1979 1985 2000 1965 2000
Bottenintnin Lake 2000 2003 2004 2005 2008
Dunlin Lake 1993
Bay Lake 1971 1997 1997
East Finger Lake 1960 1965 1979 1965
Decoy Lake 1959 1979 1984 1985 1986 1987 1997 2005 1959 1984 1986 1987 1997 2005
Pintail Lake 1990 1992 1996 1990
McLain Lake 1960 1963 1969 1972 1978 2003 2005 2007 1969 1972 1978 2005 2007
Ermine Lake 2000
Ootka, Lake 2000 2004 2010
Finger Lake 1989 2010 2017
Raven Lake 1975 2008
Hungry Lake 2008
Willow Lake 1996 1996
Sunrise Lake 1984 1989 2019 1984
Tern Lake 1969 1995 1969
Gruskka Lake 1959 1973 1979 1991 1994 2011 2013 2015 2019 1959 1973 1991 1994 2011 2019 2015
Coal Creek Lake 2022
Rhode Lake 2023

Open to Aircraft; in Wilderness

lakes adults cygnets nests
Scenic Lake 1971 1972 1975 1980 1983 1985 1997 1998 2000 2001 2002 2013 2024 1972 1975 2001 1983 2001 2002 2013
Nikolai Lake 1975 1981 2005
Taiga Lake 1985 1987 1989 1998 2001 2002 2005 2010 2015 2002 1998 2001 2002 2015
Bird Lake 1994 1997 1998 2010 1998 1998
Sandpiper Lake 1995 1998 2002 1998 1998
Bedlam Lake 1987 1988 2001 2005 2009 2013 2001 2005 2009 1988 2001
Point Lake 1972 2005 2010 2005 2010 2005
Wilderness Lake 1957 1958 1959 1960 1961 1962 1963 1964 1987 2013 1957 1958 1959 1960 1961 1963 1964 1957 1958 1959 1961 1962 1963 1964
Mull Lake 1988 1989 1990 1997 1999 2003 2007 2008 2010 2003
Cook Lake 2005
Harvey Lake 1995 2000 2002 2004 2013 2000 2002 2002 2013
Norak Lake 1979 1993 1996 2007
Vogel Lake 1961 1970 1974 2002 2005 2007 2015 2002 2005 2007 2002 2005
Kolomin Lake 1997 2000 2013 1997 2000 2013
Fox Lake 1975 1978 1982 1984 1991 1994 1999 2005 2008 2011 2013 1978 1982 1984 1991 2005 1999 2013
Tustumena Lake 1997 2013
King Lake 1961 2004 2005 2007 2015 2017 2019 2005 2007
North Kolomin Lake 2000 2000
Pothole Lake 2007
Lower Russian Lake 1979 2006 1979
Snowshoe Lake 2015
Tangerra Lake 2015

Closed to Aircraft; in Non-Wilderness

lakes adults cygnets nests
Equmen Lake 1958 1963 1969 1971 1989 2013 2015 2023
Nest Lake 1970 1974 1979 1992 2007 2008 2010 2013 2008 2013
Afonasi Lake 1958 1959 1961 1962 1963 1970 1975 2005 2015 2024 1959 1975
Marsh Lake 1958 2000
Kelly Lake 1961
Watson Lake 1959 1961 1962 1969 1970 1971 1972 1974 1975 1985 1989 1990 2004 2022 1969 1985
Headquarters Lake 1983 1988
Silver Lake 1957 1960 1962 1963 1965 1968 1989 1993 1994 1995 1998 1999 2003 2005 2013 2015 2017 2022 2023 2024 1960 1962 1963 1965 1998 1999 2003 2005 2022 1957 1960 1963 1965 1968 1998 1999 2005 2013 2017 2022 2023 2024
Mosquito Lake 1974
Lili Lake 1975 1990 1994
Forest Lake 2015 2023
Mox Lake 2015
Lower Ohmer Lake 2011 2011

Closed to Aircraft; in Wilderness

lakes adults cygnets nests
Martin Lake 1958 1959 2001
Sucker Lake 1971
Moosehorn Lake 1964 1975 1989 1991 1995 1997 2000 2001 2002 2005 2022 1989 2001 2005 1989
Fish Lake 1965 1966 1965 1965 1966
Swan Lake 1960 1961 1969 1970 1971 1974 1983 1986 1991 1994 1995 1996 1997 1998 1999 2000 2004 2005 2007 2008 2010 2011 2013 2015 2019 2022 2023 2024 1994 1995 2004 2005 2011 2019 2024 1995 2005 2024
Angler Lake 1961 1965 1966 1970 1972 1978 1995 2013 2017 2024 1965 1966 1995 2017 2024
Unnamed 1961 1963 1965 1966 1967 1968 1973 1975 1979 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2004 2005 2013 2015 1965 1966 1967 1968 1995 1996 1997 2000 2004 2005 1965 1983 1984 1985 1986 1999
Kuguyuk Lake 1958 1960 1963 1965 1966 1968 1970 1972 1979 1982 1983 1985 1990 1991 1992 2000 2001 2004 2005 1965 1968 1982 1983 1991 1992 2000 2004 2005 1963 1965 1966 1968 1972 1979 1982 1983 2000 2001 2005
Crooked Lake 1975 1997
Spruce Lake 1958 1962 1963 1996 2008 2010 2011 2013 2023 2024 1962 2008 2010 2011 2023 2013 2015 2023 2024
Little Mink Lake 1962 2013
Dipper Lake 1957 1959 1963 1966 1967 1968 1970 1971 1973 1976 1991 1995 1996 1997 1998 2000 2004 2005 2010 2013 2015 2023 2024 1957 1959 1963 1966 1967 1968 1970 1971 1991 2023 1957 1959 1963 1970 1971 2005 2023
Moose Lake 1962 1965 1970 1972 1976 1977 1978 1981 1982 1983 1984 1985 1986 1987 1988 1990 1993 1994 1995 1996 1997 2000 2002 2003 2005 2008 2011 2015 2023 1965 1981 1983 1984 1985 1986 1987 1988 1993 1995 2000 2008 2011 1970 1976 1983 1985 1986 1987 1988 1996 1997 2023
Grebe Lake 1988 1989 1991 1996 1997 2005 2008 2010 2011 2013 2015 2017 2019 2022 2023 2024 1988 1996 2005 2008 2011 2015 2019 2024 1988 1997 2005 2015 2017 2023 2024
Canoe Lake 1957 1958 1961 1962 1964 1971 2011 1957 1961 1962 1964 1957 1958 1964
Twig Lake 1970 1976 1977 1979 1980 1982 1983 1984 1985 1986 1987 1988 1989 1991 1992 1993 1994 1995 1996 1997 1998 1999 2005 2010 2023 1977 1979 1980 1982 1983 1984 1985 1986 1987 1991 1998 1999 2010 1976 1982 1983 1985 1986 1987 1989 1996 1997 1998
Camp Island Lake 1961 1962 1973 1974 1975 1980 1983 1984 1985 1986 1987 1988 1990 1991 1992 1994 1995 2000 2010 2011 2013 2015 2017 2022 2023 1962 1973 1980 1983 1984 1985 1986 1987 1988 1990 1991 1992 2010 2023 1980 1983 1984 1985 1986 1987 1988 2017 2022 2023
Rock Lake 1962 1992 1995 1996 1999 2004 1962
Wren Lake 2000 2001 2005
Loon Lake 1963 1974 1991 1994 1995 1996 1997 1999 2004 2008 2010 2015 2019 2022 1994 1997 2004
Kenaitze Lake 1978 1979 1981 1984 1990 1994 1978 1984 1978 1979 1980 1981 1984
Porcupine Lake 1977 2001 2001
Beaver Pond Lake 1975 1999 2000 2001 2004 2005 2013 2015 2004 2005
Leaf Lake 1971 1975 2015
Aspen Lake 1986 1987 1989 1998 2001 1986 1987 1998
Diamond Lake 1961 1965 1966 1973 1984 2005 2013 2015 1965 1966 1973 2005 2015 1984 2005 2015
Antler Lake 1973 1992
Muskrat Lake 1983 1994
Clam Lake 1989 1994 1996 1997 1998 2008 2010 2013 2015 2017 2024 1989 1996 2008 2010 2013 2015 2013 2017 2024
Big Mink Lake 1994 1995 2002 2005 2010 2023 2023
Rabbit Foot Lake 1965 1989 1993 1999 2008 2010 2013 2019 1965 2010 2013 2013
Meadow Lake 1973 1977 1985 1989 1990 1992 1993 1994 1995 1996 1997 1998 1999 2000 2004 2005 2013 2015 2017 2023 1973 1989 1992 1993 1994 1995 1998 1999 1998 1999
Wild Lake 1964
Berry Lake 1985
Lynx Lake 1989 2008
Embryo Lake 1999
Gavia Lake 2005 2015 1965 2005
Drake Lake 1962 1966 1967 1999 1966 1967 1999
Long Lake 1965
Round Lake 1971 1971
Weasel Lake 1993 1994 2005 2013
Eider Lake 1974 2000
Falcon Lake 2000
Kraenberi Lake 1974 1975 1997 1974 1975 1997
Ilerum Lake 1959 1975 1984 1959 1984
Otter Lake 1995 2000
Olsjold Lake 2005 2013
Birch Lake 2005 2011 2013
Teal Lake 1994
Trout Lake 2000
Kuviak Lake 2001 2001
Neckshortka Lake 1990
Lower Tangerra Lake 2008 2013
Yearling Lake 1992 1997 2005
Kakoon Lake 1975 1985 2000
Duck Lake 1977
Campers Lake 2013 2015

All Aircraft Rules to Consider:

[1] NA                                    
[2] "Closed to Aircraft in Non-Wilderness"
[3] "Closed to Aircraft in Wilderness"    
[4] "Open to Aircraft in Non-Wilderness"  
[5] "Open to Aircraft in Wilderness"      
[6] "Closed May 1 to Sept. 10"            
[7] "'Ice Open to Aircraft in Wilderness" 

Spatial Join Considerations

Note: Polygon layer appears slightly left-shifted over Topographic Basemap, but NOT with Imagery Basemap.

“Intersect” with Landable Lakes shapefile does not take into account swans on islands.

May need buffer around lakes (e.g., 300 m), but this is tricky when two lakes are closely adjacent

May want to confirm all lakes of interest are included in polygon layer

In the example below, lakes without the red outline are not in the layer.